Detail still unclear as to what the claim is for.

Details of the claim are still unclear, but the report that the case has been lodged at the Chancery Division of the High Court suggests that it is not a straightforward action for damages.

It is instead likely to be for an order that News Corporation continue to indemnify him for his legal fees under the terms of his settlement agreement. Last month Rupert and James Murdoch were asked by MPs about this indemnity at the DCMS select committee. The next day it was announced that the legal fees would no longer be paid.

David Allen Green is legal correspondent of the New Statesman and author of the Jack of Kent blog.

His legal journalism has included popularising the Simon Singh libel case and discrediting the Julian Assange myths about his extradition case. His uncovering of the Nightjack email hack by the Times was described as "masterly analysis" by Lord Justice Leveson.

David is also a solicitor and was successful in the "Twitterjoketrial" appeal at the High Court.